Luminous phase of nanosecond discharge in deionized water: morphology, propagation velocity and optical emission.

0476024 - ÚFP 2018 RIV GB eng J - Journal Article
Šimek, Milan - Pongrác, Branislav - Babický, Václav - Člupek, Martin - Lukeš, Petr
Luminous phase of nanosecond discharge in deionized water: morphology, propagation velocity and optical emission.
Plasma Sources Science & Technology. Roč. 26, č. 7 (2017), č. článku 07LT01. ISSN 0963-0252. E-ISSN 1361-6595
R&D Projects: GA ČR(CZ) GA15-12987S
Institutional support: RVO:61389021
Keywords : water * nanosecond discharge * emission spectra * breakdown
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 3.939, year: 2017
http://iopscience.iop.org/article/10.1088/1361-6595/aa758d

We employed the techniques of time-resolved intensified charge-coupled device (ICCD) microscopy and spectroscopy to register basic morphologic and emission fingerprints of micro-discharges produced in deionized water. Time resolved ICCD images evidence typical streamer-like branched filamentary morphology. Luminous discharge filaments show very fast and approximately linear initial expansion of the length with propagation velocity of ~2 × 105 m s-1. When the HV pulse reaches its maximum value, the length of the primary luminous filaments reaches ~1.3 mm. The UV-vis-NIR emission spectra show a broad-band continuum evolving during the first expansion and collapse, followed by the well-known HI/OI atomic lines occurring together with continuum emission during the second expansion and collapse. We conclude that bound-free and free-free radiative transitions are basic emission characteristics of the discharge initiation mechanism, which does not involve the formation of vapour bubbles.
Permanent Link: http://hdl.handle.net/11104/0272730